The present invention relates to an image sensing apparatus, and more particularly to an image sensing apparatus called “vision chip”, which is applied to a vision sensor and image processing. Here, the “vision chip” signifies, for example, a visual sensor chip (semiconductor or circuit) in which a super-parallel circuit structure with optical sensor circuits and processing circuits arranged for individual pixels is realized by an analog CMOS integrated circuit, and which can perform visual information processing. Among such vision chips, especially a vision chip which simulates the circuit structure and functions of an organic retina shall be called “silicon retina”.
Shown in FIG. 22 is the schematic constructional view of a vision chip. A lower view is the enlarged view of the vision chip 61. As in the enlarged view, each pixel includes an optical sensor 63 and a processing circuit 64. Image information is projected on the vision chip 61 through an optical system constructed of a lens 62, etc. The projected image information is converted into electric signals by the optical sensors 63, and the electric signals are processed in super-parallel fashion by the processing circuits 64 arranged in the respective pixels. Besides, the processing circuits 64 convert the electric signals into information which is easily understood by a higher-degree recognition apparatus such as computer or microprocessor, and which is outputted.
Owing to such a vision chip, a problem at which a prior-art image processing system based on a serial type digital computer is inapt can be solved. Various vision chips have heretofore been developed, and the principal items of visual information processing incarnated by the vision chips are, for example, “image smoothing”, “contour emphasis” and “motion detection”.
Shown in FIG. 23 is the circuit arrangement view of a single-chip system. Here, a vision chip which performs the smoothing, contour emphasis and velocity detection of an input image as one circuit example will be mentioned. In case of the single-chip system, besides an optical sensor 63, the processing circuits of a smoothing circuit 65, a contour emphasis circuit 66 and a motion detection circuit 67 must be respectively arranged in each pixel as shown in the figure.